class MyString():
    def __init__(self, capacity, fillValue=None):
        self.items = []*capacity

    def __len__(self):
        return len(self.items)

    def __str__(self):
        return str(self.items)

    def __getitem__(self, index):
        return self.items[index]


if __name__ == '__main__':
    myString = MyString(20)